Hydraulic hoist



F. JOERNS.

HYDRAULIC HolsT.

APPLICATION FILED JUNE I8, 19|?.

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Um'riF;D STATES PATENT ol-l-lcl-z.V

FREDERICK JOERNS', 0F ST. PAUL, MINNESOTA, ASSIGNOR T0 CORA A. JOERNS, 0F y ST. PAUL, MINNESOTA.

HYDRAULIC HOIST.

Specification of Letters Patent. Patented Sept. 21., 1920.

Application led June 18, 1917. Serial No. 175,363.

To all whom it may concern: v

Be it known that I, FREDERICK J oERNs a citizen of the United States, residing at t. Paul, in the county of Ramsey and State of Minnesota, have invented a new and useful Improvement in Hydraulic Hoists, of which the following is a specification.

This invention has for its object to vprovide a hydraulic hoist cylinder of a sim le construction which is adapted for use or hoisting purposes and is particularly adapted for use to hoist pivoted bodies on automobile trucks, etc., in which a certain predetermined limit of movement is required. The movement of the piston in the hoist cylinder being approximately the same during each operation of the hoist.

This invention further comprises an automatic shut-off valve which is adapted to be operated during the operation of the hoist.

The construction and features Will be clearly defined and described in the following specification.

n the drawing forming part of this speciication: I

Figure 1 is a vertical section of theho1st cylinder with connecting parts.

Fig. 2 is a section on the line 2-2 of Fi 1.

ig. 3 is a detail of a portion of the device. y

Fig. 4 is a detailsectional view of the operating valve of the device.`

In the drawing, represents a hydraulic cylinder which is adapted to be used for hoist purposes in which it is preferredto use oil or any other suitable fluids. The cyl- Ainder A is provided with a piston 1, having 'a piston rod 2 which lpasses through the head 3 of the cylinder in the usual manner and a packing box 4 is provided to preventany leakage around the piston rod 2.

The cylinder A has a base portion 5 which vis integrally formed with the cylinder having openings 6 therein in which suitable bolts can be inserted to rigidly secure the cylinder A to an automobile frame or to any other device on which it isdesired to use the hydraulic cylinder. The base portion 5 of the cylinder A is formed with a passageway 7 which is adapted to connect throu h a valve 8 with the intake passage-way 9 o a rotary gear pump 10.

The gear pump 10 is adapted to be secured to the bottom of the extending portion 11 of The pump 10 is adapted to be driven by y any suitable source of power which is connected in the usual manner by chain to the sprocket 17 The sprocket 17 is rigidly secured to the driving shaft 18 which is secured to the gear 19 of the pump 10.

The valve 8 is formed with horizontal passage-ways 20 and 21 which are adapted to be in line with the passage-ways 7 and 13 respectively when the valve is in open position or in position to operate the pistonL 1 of the cylinder A by means of the pump 10. The piston 1 is adapted to be positioned normally at the top of the cylinder A as is illustrated in Fig. l andthe cylinder A is illed with a fluid, preferably oil. The

pump 10 and connecting passage-ways tO- f gether with the passage-ways 7, 13 and 14 are also filled with oil. v

The valve 8 has an operating handle 23I which is rigidly secured to the shaft 24. The shaft 24 is rigidly secured to the body I25l of the valve 8, so that when'the handle 23 is engaged and operated, the valve can be rotated in the opening 26 in which the valve is held by the nut 27.

The operating handle 23 ofthe valve 8 is pivotally connected to the vertical rod 28 by means of the transverse pin 29 which is slidably held in the lower end of the rod 28, the pin 29 having an engaging handle 30 formed on one end and a coil spring 31 held between the end of the rod 28 and the washer 32 which is held in place on the pin 29 by means of the cotter pin 33.

The free endof the pin 29 is adapted to vengage the handle 23 in the slot 34 and the spring31 holding the pin 29 in place but allowing the pin 29 to be disengaged from the slot 34 by engaging the end 30 and pulling outward 0n the same. The rod 28 is slidably held to the cylinder A by means of the brackets 35 and 36. The rod 28 is bent so that the lower end will extend down alongside of the valve operating handle 23 and the upper end extending in line with the center line of the cylinder A.

The upper end of the rod 28 has an 'engaging head 37 secured thereto and a coil spring 38 held between the head 37 and the bearing of the bracket 35 so that the rod 28 is normally held by the spring 38 in elevated position as illustrated in Fig. 1 in full lines.

The cylinder A is formed with flat surfaces 39 on opposite sides which extend longitudinally of the c linder A and\are parallel to each other. wo pairs of angle irons 40 are bolted to the flat surfaces 39 and extend parallel to each other vertically above the cylinder A, thetop of the angle irons 40 being broken away in the drawing but it being understood that they are connected to any other suitable mechanism above the cylinder A which is adapted to be-operated by the hoist. The pairs of angle irons 40 form channels or guide-ways 41 between their inner faces. i

The guide-ways 41 are adapted to form a guide for a horizontal arm 42 which is rigidly secured to the piston rod 2 in any suitable manner and is adapted to travel up and downl in the guide-ways 41 when the piston 1 is operated. The horizontal arm 42 is formed with a downwardly bent portion 43 which extends beyond the guide-way 41 on o-ne side of the cylinder. When the iston 1 is operated by the pump 10, the horizontal arm will be drawn down into the position illustrated in Fig. 1 in dotted out-` In operation of the hoist cylinder A, the

valve 8 is placed in the position illustrated in Fig. 1 and the pump 10 rotated by suitable operating mechanism from any source of power (the source of power and connecting mechanism not being illustrated in the drawing). As the pump rotates, it will draw the oil through the passage-way 7, valve passageway20 and passage-way 9 from the bottom of the cylinder chamber 22 and discharge it through the passageway 12 into the passage-way 13 through the valve passage-way 21 and up through the passage-way 14 through the opening 16 into the cylinder chamber 15 creating a downward pressure against lthe piston 1 which causes the piston to move downward in the cylinder A. Thus as the oil is drawn from the chamber 22 of the cylinder and dis- 'chargedto the other side of the piston 1 into the chamber 15, the piston will move downward into the position illustrated in dotted outline in Fig. 1.

lVhen the valve 8 is in the shut-off position illustrated in'Fig. 1 in dotted outlines,

the passage-ways 20 and 21 will extend vertically lacross the passage-ways 7 and 13 and the portion 44 of the valve will close off the passage-ways 7 and 14 from communication with the pump 10 locking the piston 1 in the position illustrated in dotted outlinein Fig. 1, the center wall 45 of the valve 8 also cutting off communication from the pump passages to the passages 7and 14 but allowing fluid oroil to travel or be bypassed through passage-way 21 of the valve and through the pump and its connecting passage-ways, thereby allowing the pump to continue to rotate wlthout any damage and allowing a by-passing of the oil circulated by the pump through the valve 8.

When it is desired to. turn the piston 1 of the hoist cylinder A back to normal position at the top of the cylinder, the pump 10 is stopped and the pin 29 is disengaged from the handle23 and the handle 23 moved to rotate the valve 8 a half a turn so that the valve will be in the position illustrated in Fig. 4. The passage-way 21 forming a bypass so as to allow the oil to pass back down through the passage-way 14 through the passage-way 21 of the valve and into lthe cylinder chamber 22 through the passageway 7, it being understood that there is a suliicient pressure against the mechanism connecting the piston rod so as to draw the piston back into its upper normal position. The valve 8 has three distinct positions: first, operating or open position as illustrated in full lines in Fig. 1; second, pump by-passing and piston locking position illustrated in dotted outline in Fig. 1 and third, cylinder or pistonl by-passing and pump locking position.

The operation of the valve into its second position is automatic by the depressing of the arm 42 and when the piston returns to normal position at'thetop of the cylinder, the rod 28 returns automatically by means of the spring 38 and the pin 29 can be inserted again into the slot 34 of the handle 23. It is obvious that any suitable mechanism such as cross arms and sheaves can be connected to the piston rod 2 together with cables, etc., to form the desired hoist for the particular occasion, but the principal features and elements of the hoist are the cylinder, together with the valve, pump and other connecting mechanism. For this reason the `last mentioned elements only have been illustrated in the drawing.

While I have illustrated one particular form and construction of mechanism in the drawings, I desire to have it understood that this construction is only illustrative and that v the invention can be carried out by other means and applied to uses other than those above set forth Within the scope of the following claims:

I claim- 1. In a device of the class described, a cylinder having a movable piston therein, a pump, passage-Ways connecting said pump with either end of said cylinder, a three position valve in said passage-Ways, said valve being formed With tvvo separate passage- Ways so that when said valve is in open position, said pump can draw oil from said cylinder to transfer it from one side of the piston to the other, the second position, of

said Valve locking the oil in said cylinder and forming a by-pass for the passage-Ways of said pump and a third position of said valve forming a by-pass for the oil in said cylinder to pass from one side of piston to the other and closing the passage-Ways connecting said pump With said cylinder.

2. In a device of the class described, a cylinder and piston movably held therein, a pump, passage-Ways connecting said pump With said cylinder to draw oil from the bottom of said cylinder and deliver it to the top thereof to operate said piston, a valve in said passage-Ways, transverse openings formed in the same plane through said valve, and connecting means for automatically closing said passage-Ways so as to automatically lock said piston in said cylinder and to simultaneously form a by-pass through said valve for the connecting passages from said pump when said piston ireaches its ovvnward limit of movement in said cylin- 3. In a device of the class described, a hydraulic cylinder having a movable piston therein, a pump for transferring oil from one side to the other of said piston, passage- Ways connecting said pump with said cylinder, a controller valve in said passage-Ways having means for opening said passage-Ways in one position, for closing said passage- Ways to said cylinder and by-passing said passages ofsaid pump in another position and to connect said passage-Ways with either side of said piston and close the passages from said pump in a third position.

FREDERICK JOERNS. i 

